Material heating and handling means



Oct. 14, 1952 c. A. NICHOLS EI'AL 2,613,450

MATERIAL HEATING AND HANDLING MEANS Original Filed Aug. 22, 1946 6 Sheets-Sheet l Oct. 14, 1952 c. NICHOLS ETAL 2,513,450

MATERIAL HEATING AND HANDLING MEANS Original Filed Aug. 22, .1946 I 6 Sheets-Sheet 2 Z INVENTORS' MW Wm Oct. 14, 1952 c. A. NICHOLS ETAL 2,613,450

MATERIAL HEATING AND HANDLING MEANS Original Filed Aug. 22, 1946 6 Sheets-Sheet 3 //V\/E-A/TOB$ CI AELES ,4. MQI/OI-S 8058544 5. Bow Ea 650665 L IVE/see /AMES R. EDWARDS W11. L /AM /1. F1. 5 Ted/ fi AROLD h. r72 00v 5,4611. 6- 6A PLE c. A. NICHOLS ETAL 2,613,450

MATERIAL HEATING AND HANDLING MEANS Original Filed Aug. 22, 1946 Oct 14, 1952 6 Sheets-Sheet 4 Oct. 14, 1952 c. A. NICHOLS- ETAL 2,613,450

MATERIAL HEATING AND HANDLING MEANS Original Filed Aug. 22, 1946 6 Sheets-Sheet 6 7'0 CUIPREN T SOUPCE Patented Oct. 14, 1952 MATERIAL HEATING AND HANDLING MEANS Charles A. Nichols, Russell B. Bower,.George. L.. Weiser, James R. Edwards, William A. Fletcher, and Harold W. McCoy, Anderson, Ind., and Basil S. Sample, Danville, IllJ, assignors to GeneralMotors Corporation, Detroit, Micln, a corporation of Delaware Original application August 22, 1946,- Serial No.

692,274. Divided and this applicationJune 12, 1948, Serial No. 32,605

9 claimsr 1 This application isa division ofapplication Serial No. 692,274, filed August 22; 1946, which discloses a method of preheating molding material while in comminntedv form and apparatus for carrying on the method and, in coordination with the apparatus,, an injection moldingmachine which receives the preheated comminuted material and causes it to be forced into mold cavities and therein to be cured under heat and pressure.

The invention. claimed. in this application relates to apparatus for handling. and preheatingv the, comminuted molding. material. The disclosed embodiment of the invention provides a hopper for receiving comminuted molding materiaLfa measuring device which receives a predetermined quantity of materialv from the hopper. and dumps the. material into a vessel from which the material is" transferred by air pressure to. the top of a preheating. chamber inwhich hot air is ascending at such velocity as to cause the material 'to be suspended in the chamber while being heated; At the end of," the preheating period, the heating chamber is caused to discharge its contents into'a compression chamber of" a molding. die. A companion molding. die is caused. to be pressed against the die having the compression chamber and the preheated material therein is forced by a piston or, rain out of the compression chamber through'ductsjor runners connected with the die cavities in which the. material is'cured under heat and pressure.

Further objects and advantages of" the; present invention willbe apparent from the following description, reference being had toi'the accompanying drawings, wherein a preferred embodiment of the present invention is" clearly shown.

In the drawings: v

Fig. 1 is'a front elevation of the molding machine and materialhandling apparatus.

Fig. 2 is a side elevation looking-in the direction of arrow 2' of Fig. l.

Fig-'3 is a side elevation; partly broken away; of the apparatus for measuring charges ofmolding material and causing the sameto-be transferred to apparatus for heating the material prior to discharge into a mold. This view is drawn to a-larger-scale than the view ofthis apparatuswhich appears in Fig. 1.

Figs. 4 and 5 are views taken in the directions of arrows 4 and 5, respectively, of Fig. 3.

Fig. 6 is a sectional view on-line-Ii-B of Fig. 4.

Fig-'7' isa sectional view' on line I-l of Fig. 6.

Fig; 8 is a sectional view on line 88' of Fig. 6.

Fig. 9 is" a sectional; fragmentary view of the ports an upper die I21.

prior to discharge into a mold and this view is taken principally on the line 99 of Fig. 2, but with tube 4H lowered.

Fig. 10 is a fragmentary plan view in'the direction of arrow III of Fig. 9, but with part 380 moved to the left.

Fig. 11 is a fragmentary, sectional view on the line. II-II of Fig. 10.

Fig. 12 is a fragmentary, end view in the directionofarrow I2 of Fig. 9.

Fig. 13' is a sectional view on line I3--I3 of Fig. '11.

Fig. 14 is asectional view on line I4'-I4- of Fig. 9.

Fig. '15 is a diagram of" the valves and controls pertaining to the apparatus showing in Figs. 3 -'-14.

Referring chiefly to Figs. 1 and 2, the -mold-- ing machine comprises a base I00 supporting. posts [III and I02 whichsupport a bar I09 which supports a cylinder II'I), which receives a piston (not shown) connected to a bar I20 which sup- Bar I20 is guided by the posts IUI and I02. The upper die IZI is adapted to engage either one or two lower dies I22; I23 mounted on an oscillatabletable I25. Thesedies are secured 'to their respective supports by angle bars I24 and screws I24a- (Fig; Table I25 is rotated 180 alternately in opposite direction by an hydraulic servo operated mechanism including a servo cylinder I45.

Each lower mold I22- or I23 has a compression cylinder containing a ram or piston which, whenits mold is under the mold I2I, is operated to effect ejection of the molding material by an hydraulic servo including a cylinder I; and which, when its mold is in the loading position, is operated by an hydraulic servo including a cylinder 200' for the purpose of ejecting molded parts through the operation of ejector pins operatively connected with the ram.

The molding material, either in powder form or granular, is placed in a hopper 300 (Fig. 2)

: from which it descends to ameasuring device I compressed air is appliedto blow the contents of the hopper 360 through a pipe 318 to a heating chamber within a funnel or thermoclone 380 through which ascends the combustion products and hot air from a stove 400. While the thermoclone -38!) is connected with the stove 400,

1 ring 323 surrounding the tube 313.

a current of hot air from the stove ascends and causes the particles of molding powder to be suspended and to be heated a certain amount so that there is started a chemical reaction which is completed after the heated material is received by the cavities of the upper and lower dies. After the heating cycle, the thermoclone 388 is moved into alignment with a telescopic discharge pipe 411 which is lowered at the proper time as to discharge the contents of the thermoclone into a lower die when in the loading position. The foregoing is a brief outline of the method of handling the molding material before it is loaded into a lower die.

Referring to Figs. 3 and 6, it will be seen that the loading hopper 308 has a flange 331 by which it is attached by screws 302 to a plate 383 having a downwardly flaring opening 3114. Plate 333 is pivotally supported by stud 335 upon the frame 31 1 of the measuring device 3 I 8. As shown in Fig. 5, plate 383 has a notch 3135 for receiving a stud 331 which receives a nut 3113 and a washer 383. By loosening the nut 335a on stud 3115 and the nut 3133 on the stud 3115, the hopper and its mounting can be swung horizontally away from the opening 312 in the frame 311. Thus the hopper 333 can be moved so as to provide access into the interior of the frame 311 without lifting the hopper from the frame.

Frame 311 rotatably supports a measuring tube 313 (Fig. 6) having an oblong opening 314, through which molding powder can descend from the hopper through the passages 334 and 312. The amount of powder which the tube 313 receives depends upon the spacing between a flxed disc 315 and a movable disc 315. Disc 3115 is integral with a rod 311 integral with a disc 318. A tube 313 which is slidable within the tube 313 is attached to the discs 315 and 318. Screws 3211 connect the disc 318 with a disc 321 which is recessed to receive, with a running fit, the flanged head 322 of a screw 323 having a turn knob 324. Screw 323 is threaded through hub 325 of a disc 326 with screws 321 attached to a By tightening the screws 321, the disc 328 is caused to move toward the disc 323 until the former engages a split wire snap ring 329 located in a groove provided by the tube 313. The hub 325 of disc 323 is journalled in a ball bearing 333 supported by a cover plate 331 which screws 332 attach to the frame 311 together with a cover plate, 333. The location of the hub 325 relative to the bearing 338 is fixed by nuts 334 and 335 threaded on the hub 325, nut 334 being engageable with the inner race of bearing 338. By turning the knob 324, the screw 323 is threaded in and out of the hub 325 and the tube 319 and the disc 31B are caused to move horizontally in order to cause the tube 313 to receive a predetermined amount of molding powder. Fig. 6 shows the disc 316 in the position in which the tube 313 will receive the maximum measured amount of molding material. The screw 323 is held in a desired position of adjustment by a nut 333 which can be tightened against the right end of the hub 325 of disc 326 and which can be held in adjusted position by a lock nut 331. Nuts 338 and 331 have annular flanges which abut each other when these nuts are in engagement. The nuts can be turned by a spanner ring engageable with holes 331a or 3315a in the flanges of these nuts.

The disc 315 which supports the left end of the tube 313 is integral with a shaft 340 journaled in a bearing 341 supported by a block 342 with the hopper 351].

screws 343 together with a plate 344 attached to the frame 311. Block 343 receives a gear 345 connected with the shaft 345. As shown in Fig. 4, gear 345 meshes with a rack 346 guided for vertical movement by the lock 343 and attached to a rod 341 connected with a piston 350a (Fig. 15) in a cylinder 350. Cylinder 350 is attached to a frame 343 which supports the frame 311. Rod 341 is connected also with a block 351 carrying a roller 352 for engaging a cam lever 353 pivotally supported at 354 by the frame 311 and urged clockwise by a spring 355 received by a block 355 attached by screws 351 to the frame 311. Spring 355 urges downwardly a plunger 3523, thereby causing the lever 353 to be urged against the roller 352. Movement of the lever 353 controls the opening and closing of a valve 359 (Fig. 6) in the mouth of the hopper 361]. Hopper36il has a flange 381 which is screwed to the frame 3| 1. Screws 352 attached to the hopper a mouthpiece 333 providing a seat for the valve 359 which has a stem 354 connected by a pin 365 with a lever 3% attached to a shaft 351 journaled in a tube 368 (Fig. '1) welded to Shaft 351 carries an arm 359 which as shown in Fig. 3, is connected by pin 313, link 311' and pin 312 with lever 353.

When piston 353a of cylinder 35!! (Fig. 4) moves down, tube 313 is rotated During such movement, the valve 359 is moved down so that the contents of the tube is discharged into the hopper 358. As it discharges, some of it may fall over the knife edge 333a of the lever 338. After the tube 313 has been discharged,

, the piston 353a. moves up so as to return the tube 313 to position for receiving more powder from the hopper 33D and so as to move the valve 359 in mouth-closing position. The rotation of the tube 313 is limited by the engagement of a lug 315a (Fig. 8) of disc 315 with either of two stop screws 315D threaded into the frame 311 and retained in adjusted position by lock nuts 3150.

Pipe 411, connected with a compressed air source through a valve 411 (Fig. 15) may be connected by a two-way valve 411a (Fig. 6) either with pipe 311a or with pipe 3111) leading into the hopper 353. Some kinds of material are discharged from the hopper 3513 when compressed air is directed upon it, and other kinds when the air is introduced near the outlet, which is connected by a coupling 318a with the pipe 318. Any dust laden air escaping past the valve 359 is discharged through pipe 316 to a dust collector 315, the bottom of which may be connected with a bag not shown.

Referring to Fig. 9, thermoclone 383 is provided with a fixed bafiie 381 and an adjustable baffle 382 of conical formation suspended by a rod 383 threaded through a nut 3113 supported by rods 335 extending through clamps 386 which pins 381 attach together with the bafiie 381 to the thermoclone 383. At its lower end, the thermoclone is welded to a flange 388, which screws 389 attach to a slidable plate 393 which, as shown in Fig. 14, is connected with horizontally movable side plates 391 having lugs 332 received by grooves 393 in a bar 394 which screws 335 attach to a spacer plate 398 and to a bracket 391 which includes a vertical plate 333 (Fig. 12) attached to another vertical plate 399 which is attached to the bar 1119 which supports the die closing cylinder 1 111 (Fig. 2). Plate 3118 supports the stove 430 into which there is introduced at 401 under pressure a combustible gas, combustion being supported by air previously mixed with the gas. Additional air to furnish necessary air volumeise introduced through aside caused to be heatedtotsuchextent that thereisinitiated chemical: reaction: further carried on. in the: die cavities where, under pressure as well. as heat; the curing oflthe resin is completed.

..After the preheating. cycle int-the thermoclone 38B has'be'encompletedpthe thermoclone is moved bodily. to the: left fromithe' position'shown in Figs. 1. and: 9 by meansincludingia cylinder' iifl having a piston 410a (Fig.315): connected with a rod 4H which a plate 4 l2 swiveledly'connects it to a plate 413 which is connected with the plates 390.:and 391 (Fig. 1.4). Atthe propertime, thepiston MM is caused'tov moveleit to move the lower end of the thermoclone away from the stove outlet 46-3 and into communicationwith a funnel-like opening 415 in bar 394 whence the; contents of the thermoclone -are discharged bygravity into the open die at the-loading station: through a telescopic tube comprising members 413. and4i-1 whichv are caused to be extended; while the con tents of the thermoclone 380 is being discharged.

The upper end of; tube 456 is attached to a flange 418' attached to the undersideof bar 334. The tube 411 is attached to a platei4-l3 (Fig. 11) attached to a bracket 420 caused by screws 42! to beclamped around a tube 422.- Tube 422 telescopically engagesa tube423: attached at its upper end to a bracket 424 attached as. shown in Fig.

to theplates 339 and. 109;: Tube-423 has a side slot 425 for receiving a lug 426 '(Fig; 13) integral with a plate 421 which screws 428 attach to a ring 429 attached to the tube 422. The tube 4!! is supported upon a flange 43!! of airod 434 attached to' the'rod 432 of a piston 44Ba.(Fig. 15) received bya cylinder 440 which is: sup-ported by the bracket 4'24. Piston 440a'ca-nmove down until it bottoms in cylinder 440. The discharge tube 4|! is lowered when the time comes to fill a lower die. After the die has been filled, compressed air is caused'to enter the lower end 'of the cylinder 440-inorder to raise rod 432', flange 43d, lug 426,'

bracket 429, tube 422 and tube 411.. It is desirable that the tube 4" be up while unloading the work from the die at the loading station and preparing it from'the reception of a .charge of preheated molding material.

The control of'the mechanism for handling the molding powder isillustrated diagrammatically inFig. 15. The admission of pressure fluid (compressed air) to the ends of cylinders 350,.4l8 and 440- is controlled by a valve unit 44] which includes a movable valve 442 for controlling the distribution ofpressure fluid entering through a pipe-443 and an inletport444' to either of distribution ports. 445 and 446 connected respectively with pipes 44! and 448; Pipe 44'! is connected with the lower end of cylinder 353 with the left end of cylinder 4H] and with the lower end of cylinder 440. Therefore when the valve 442 is in the position shown, piston 350a will be forced up, piston 4l0a Will befo'rced right and piston 440a will be forced up. Pipe*448 is connected with the upperends of cylinders 350 and 440 and through a restriction 449 with the. right end of cylinder 410. whenvalve 442iscaused toxmovexdowmthe.

right end of cylinder 4|Lfl and the upper ends' of the cylinders 359: and 444 are connected with. thepressure pipe'44'3 which results in the left movei-;

ment of piston i l Ga and downwardmovement: of;

pistons 356w and 440d. The restriction 449: provides for downward movement. of piston 44m aheadof left' movement-of. piston 4mm. Therefore the discharge tube" 4H: is lowered ahead of? movement of the thermoclonermil over the dis-- charge outleti4 l 5. The valve 44 l. :providesiexhaust ports dfih and 45 l which are so controlled that when'pressure fiuidis applied to one end of each of the cylinders 355i, 410' and 440, the. otherends will be connected with exhaust: or withidrain in;

case hydraulic pressure is used. Valve 442 car-. ries a roller-453 for. engaging'a control cam. 454 againsttwhichthe roller: is urged by a. spring 455.1 Care 454 efiects the dumping of the. contents of the measuring devic'eintothe hopper 360 and the closing of the hopper and return of themeasurine device toposition for receiving: another charge while effecting the movements for discharge. of the thermoclone and its return to the stove;

While the hopper 360 is closed atthe top-, compressed air is caused to pass frompipe 443- and through valve unit 4' and pipe'A'H into the hopper to force the molding" material. into-the thermoclone. Unit 4' has a movable valver4l2 carrying a rollerwhichaspringj4l5 urgesagainst a cam 414 which depressesthe valve member 412 after valvemember 442 rises.

Cams 454 and. 414 are rotated counterclockwisev by a shaft 480' which carriesiatswitch operating cam 482 which is engaged bya ro1ler1484 carried by a plunger 48.6 slidablelin. switch unit 488. and urged upwardly by a spring notzshown; Unit 488 contains a switch S3. Near theend of one revolution of shaft Hi3, switch S3 is opened by cam.482 to disconnect motor M3 fromitscurrent source. The motor M3 coasts to a stop .at the end of one revolution of shaft. 480. To start the motor M3, a switch S5 is closed to by-pass switch S3 by means which,- as disclosed in application Serial #692,274, operates near the end of the curing cycle. Shaft 48% is connected by spurgears 490 and 491 and by worm gear 492 and worm 493 with a cam shaft operating motor M3.

Fig. 15. shows the status of the apparatus operated by motor M3 at the end of its cycle whencam 484 has opened the motor stopping switch S3. When switch S3 is by-passed by the switch S5, motorv M3 starts rotating shaft 480 counterclockwise, Cam 414 immediately lowers valve 412 to cause the measured charge in hopper 360 to be transferred to the thermoclone. After about 270 rotation of shaft 480 during which'the charge is heated, cam 454 lowers valve 442 to cause the thermoclone to discharge its contents into a die at the loading station. Concurrently, piston 350a moves down to cause a measured charge to be received by hopper 360. Before the end of one revolution of shaft 4811, switch S5' is opened so that the switch S3 iseffective to" cause the motor M3 to sto at the end of one revolution of shaft 480.

The apparatus'facilitates the injection molding of thermosetting plastic material, phenolic resins for example, by providing for the preheating of the material in comminutedform as it is customarily received from the supplier. The charge of powdered (comminuted) plastic material is introduced at the top of the thermoclon and the particles fall until they reach a level where overcome the force of gravity action on the particles, so that the particles remain suspended, more or less, stationary. This suspension is inherently stable, since a further downward movement of the particles will bring them into a region of greater air velocity thereby forcing them up, while the reverse is true of upward movement of the particles. Substantially uniform heating of all the particles of the charge is rapidly obtained. The temperature to which the particles are heated may depend on the kind of plastic material. Some kinds of thermosetting phenolic material which requires that the temperatures of the dies be 280 F. to 400 F. should be heated in the thermoclone to about 250 F. to 275 F. For this purpose, the temperature of the hot air entering the bottom of the thermoclone may be about 280 F. to 400 F. and its entering velocity about 3600 feet per minute. The duration of the heating cycle will depend on the quantity of the charge to be heated.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. Means for uniformly heating loose molding powder comprising means for supplying a heated drying gas, a horizontal plate, a series of ducts encompassed by the plate communicating with the means for supplying the heated drying gas and for directing the heated gas upwardly through the plate, a powder discharge passageway in the plate spaced from the ducts, a carriage resting upon and slidable over the plate, and rectilinear guide rail mounted for guiding the carriage over the plate, a vertical passageway through the carriage, a funnel member mounted over the passageway, means for reciprocating the carriage on the plate while being guided by the rails to alternately register with th ducts or with the discharge passageway.

2. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate and mean for directing heated air upwardly therethrough, a discharge passageway in the plate spaced from the air ducts, a slide carriage, a vertical passageway through the carriage, a funnel mounted over the passageway, said funnel being provided with means for preventing the powder in said funnel from being blown out of the funnel during the drying operation, and means for reciprocating the carriage on the plate between the rails to register With the ducts and with the discharge passageway.

3. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate and means for directing heated air upwardly therethrough, a discharge passageway in the plate spaced from the air ducts, a slide carriage, a vertical passageway through the carriage, a funnel mounted over the passageway, said funnel being provided with means for preventing the powder in said funnel from being blown out of the funnel during the drying operation, and means for reciprocating the carriage on the plate between the rails to register with the ducts and with the discharge passageway.

4. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate, means for directing heated air upwardly therethrough, a discharge passageway in the plate spaced from the air ducts, a slide car- Lil riage, a vertical passageway through the carriage. a vessel supported in said passageway and comprising a container for the powder to be heated, said vessel being provided with means for preventing the powder in saidvessel from being blown out of the vessel during the drying operation, and means for reciprocating the carriage on the plate between the rails to register with the ducts and with the discharge passageway.

5. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate and means for directing air under pressure upwardly therethrough, means for heating said air prior to its delivery to the plate, a discharge passageway in the plate spaced from the air ducts, a slide carriage, a vertical passageway through the carriage, a funnel mounted over the passageway, said funnel being provided with means for preventing the powder in said funnel from being blown out of the funnel during the drying operation, and means for reciprocating the carriage on the plate between the rails to re ister with the ducts and with the discharge passageway.

6. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate and means for directing air upwardly therethrough, means for heating said air prior to its delivery to the plate, means for regulating the temperature of the air, a discharge passageway in the plate spaced from the air ducts, a slide carriage, a vertical passageway through the carriage, a funnel mounted over the passageway, said funnel being provided with means for preventing the powder in said funnel from being blown out of the funnel during the drying operation, and means for reciprocating the carriage on the plate between the rails to register with the ducts and with the discharge passageway.

7. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate and means for directing heated air upwardly through the plate, a discharge passageway in the plate spaced from the air ducts, a slide carriage on the plate, a vertical passageway through the carriage, a funnel mounted over the passageway, said funnel being provided with means for preventing the powder in said funnel from being blown out of the funnel during the drying operation, a piston for the carriage and means to reciprocate the piston and cause the carriage to move between the rails.

8. Means for uniformly heating loose molding powder comprising a horizontal plate, a pair of straight parallel rails thereon, a series of ducts in the plate and means for directing heated air upwardly therethrough, a discharge passageway in the plate spaced from the air ducts, a slide carriage on the plate, a vertical passageway through the carriage, a funnel mounted over the passageway, said funnel being provided with means for preventing the powder in said funnel from being blown out of the funnel during the drying operation, a piston for the carriage and pneumatic means to reciprocate the piston and cause the carriage to move between the rails.

c 9. Apparatus for handling molding material 101' use in die molding operations comprising a material heating vessel having a discharge open-' ing in the bottom thereof through which the heated material is discharged by the effect of gravity,

means for introducing the material to REFERENCES CITED The following references are of record in the 2;

file of this patent:

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